This example shows a React component that renders a minimal smiley-face arc using D3’s `arc` generator, though the visible output is currently only a static header. The code defines parameters for the mouth, eyes, and stroke width, and computes the mouth’s path with `d3.arc`, setting inner and outer radii and angular start and end points. It uses React 16.7 and D3 v6, with the arc logged to the console but not yet drawn to the screen.